A few days (OK, OK, a week) later than I’d hoped, but done, nonetheless.
Wanna see?
Sure you do!

This FO says, "Buttons are for followers."
That’s right, no buttons.
The fabric is a super-soft terry that would, I think, look overdone with buttons. (Full disclosure: I checked out my button stash before arriving at this conclusion. Nothing looked “soft” enough or was the right shade of lilac.)
Instead, I crocheted (that’s right, folks, the C word!) a chain about 7 inches long, using a section of the Lu Lu that was folded double to eliminate a hanging tail. When I ran out of yarn in the doubled section, I did the next stitch into the right front of the sweater at the point where the white yarn borders the lilac. Then I did a row of single crochet around the neck and down to the lilac section on the left front. I stopped there, broke the yarn and wove in the end. Then I did a repeat of the folded-yarn crochet-chain thingy for the other side, attaching it with a couple of single crochets to the appropriate join spot.
I tied a little bow and stood back to see how I liked it… and I did!
Here’s a closer shot of the neck/tie treatment:

Such a sweet little bow!
It sure didn’t escape or upset me that this has to be the easiest way to make a fastening for this particular sweater. And so perfect here!
Arianna’s sweater looks like a house robe, albeit a really small one, doncha think? Not just because of the fabric’s texture or the tie-closure, but also ’cause I made the lilac section about 3 inches “longer” than the pattern calls for at this size. That made the proportions more long-robe-like than sweater-like, but I love the idea of wrapping a little Arianna in its softness from neck to ankle… at least till she gets a few weeks or months of growth on her.
I finished this in the wee hours of Saturday morning, while on my lunch break, and showed it to a few of the women I work with. The result every time: “Aaaaaw! That’s so sweet!” and “So cute!” and “So soft!” and “Adorable!”
Wonder what I’ll make for Arianna next… probably a hat and some booties to match, as I have more than a full skein left of the Heaven Lite, with enough of the Lu Lu for trim work. Sounds like a plan!
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Still waiting for some suggestions on washing solutions for the Noro Silk Garden. Anyone?
I’d use Eucalan (because I use it for all my handwashables), but if you don’t have a no-rinse shampoo on hand, then either Woolite or a mild shampoo in lukewarm water should do the trick.
The baby sweater is adorable! Very clever closure. And for an extra-special bonus, I think the baby would be less likely to pull off the cords and try to swallow them than she would be a button!